This book deals with the relationship between coercion and the theory of cause, where coercion must be the motive for the conclusion of a contract. This means that there is a strong relationship between coercion and cause.The cause must exist, therefore; the problem of this research arises from this point. Does the cause exist with the presence of coercion that led this will to contract?Which means that the motive for concluding the contract is the same as coercion. The defect is not in a condition of coercion, but rather the defect is in a condition of cause.Based on this, why do laws arrange the provisions of coercion and not the provisions of cause on this hypothesis?The present research presents the truth of the relationship between coercion, cause, and the legal provision that we are supposed to reach through the presence of this assumption.